H323和SIP的比较文件.docx

1、H323和SIP的比较文件北电出版的关于H323和SIP的比较文件 TITLE: A Comparison of H.323v4 and SIP DATE: 5th January 2000 SOURCE: Nortel Networks ABSTRACT: This contribution compares and contrasts SIP to H.323v4 to help aid operators and vendors in the selection of a single least common denominator control protocol for the p

2、s domain or perhaps more appropriately plane of UMTS Release 2000. The format anticipates the concerns, in the form of questions, which may arise from 3GPP members. RECOMMENDATION: For facilitation of protocol selection. Note: Every effort has been made to ensure the completeness and accuracy of thi

3、s document. Any inaccuracies or discrepancies are unintentional and should be brought to the attention of Nortel Networks for clarification/correction. 1 BACKGROUND 1.1 KEY MOTIVATORS IN NETWORK PROTOCOL RECONSIDERATION: 1.2 PROTOCOL SELECTION OPTIONS: 1.3 SCOPE OF THE REQUESTED EFFORT: 1.4 KEY ASSU

4、MPTIONS FOR THE ANALYSIS: 2 H.323/SIP COMPARISON: IMPORTANT FACTORS TO CONSIDER WHEN CHOOSING A PROTOCOL 2.1 COMPLEXITY 2.1.1 Message set comparison 2.1.2 Encoding, parsing and generation 2.1.3 Debugging 2.1.4 Reuse of existing code and procedures 2.1.5 Service and feature implementation and protoco

5、l interactions 2.1.6 Options and methods for implementing services that are available in the protocol 2.1.7 Interworking with the PSTN 2.1.8 Implementation in UMTS Release 2000 network elements and user devices 2.2 EXTENSIBILITY 2.2.1 Compatibility among versions (built into the protocol?) 2.2.2 Fea

6、ture evolution 2.2.3 Ability for carriers to define own features and services 2.2.4 Modularity of the protocol to allow for the easy evolution to new services and features 2.2.5 Ability to work with existing and new multimedia codecs 2.2.6 Third party call control mechanisms 2.3 SCALABILITY 2.3.1 Su

7、pport for large numbers of domains (wide area addressing, user location, etc.) 2.3.2 Ability to handle large numbers of calls 2.3.3 Maintaining of call states (stateless or stateful) effect on scalability 2.3.4 Elements that must maintain states 2.3.5 Signaling message processing 2.3.6 Conference si

8、zes, conference control (centralized vs. distributed) 2.4 RESOURCE UTILIZATION AND MANAGEMENT 2.4.1 Resource required during the call 2.4.2 Resource minimization 2.4.3 If compression is applied to each signaling protocol (H.323 and SIP), what gains could be achieved percentage wise. 2.5 SERVICES 2.5

9、.1 Services supported 2.5.2 Delay times to acquire services, both basic (such as dial tone or post-dial delay) and supplementary services 2.5.3 Billing and accounting 2.5.4 Comparison of services with existing wireless or wireline services (do the same set of services exist, not necessarily implemen

10、ted the same). 35 2.5.5 Capabilities exchange services provided in the protocol 2.5.6 Personal mobility services (delivery of services wherever the subscriber is located, network independent) and location based services 36 2.5.7 Interworking and interoperability with legacy networks (wireline and wi

11、reless) 2.5.8 Interworking and interoperability with other IP call control protocols (e.g., cable) 2.5.9 Security services provided, authentication of users and network elements, data privacy and encipherment 2.6 WIRELESS STANDARDS CONSIDERATION 2.6.1 Where and how would any wireless specific change

12、s to the protocol be implemented? 2.7 OA&M 40 2.7.1 What OA&M procedures are available? 2.7.2 What level of fault detection and monitoring are available? 3 H.323/SIP COMPARISON QUESTIONS 3.1 DESCRIBE AND COMPARE THE PURPOSE AND INTENT OF THE H.323 AND SIP PROTOCOLS. CONSIDER WHY THEY WERE DEVELOPED,

13、 WHAT NETWORKS THEY WERE DEVELOPED FOR, WHAT SERVICES THEY WERE INTENDED TO SUPPORT/PROVIDE, ETC. 3.1.1 H.323 3.1.2 SIP 42 3.1.3 Conclusion: 3.2 DESCRIBE AND COMPARE THE STATUS OF THE H.323-SERIES PROTOCOL STANDARDIZATION AND THE SIP PROTOCOL, IN TERMS OF AVAILABILITY AND MATURITY OF STANDARDS FOR P

14、RODUCT DEVELOPMENT. 3.3 WHAT STANDARDS CHANGES ARE ENVISIONED TO H.323, AND ASSOCIATED STANDARDS, TO SUPPORT THE UMTS RELEASE 2000 ARCHITECTURE? WHAT STANDARDS CHANGES ARE ENVISIONED TO SIP, AND ASSOCIATED STANDARDS, TO SUPPORT THE UMTS RELEASE 2000 ARCHITECTURE? WHAT IS THE ESTIMATED DEVELOPMENT TI

15、ME FOR AND AVAILABILITY EACH OF THESE STANDARDS? COMPARE THE STANDARDS PROCESS FOR H.323 AND SIP. 3.4 DESCRIBE AND COMPARE THE OVERALL COMPLEXITY OF IMPLEMENTING THE H.323 AND ASSOCIATED MULTIMEDIA CONTROL PROTOCOLS, AND THE SIP PROTOCOL. 3.5 DESCRIBE AND COMPARE THE COMPLEXITY OF IMPLEMENTING H.323

16、 AND ASSOCIATED PROTOCOLS, AND THE SIP PROTOCOL, IN THE UMTS RELEASE 2000 ARCHITECTURE. 3.6 HOW WIDESPREAD DO YOU ENVISION H.323 DEPLOYMENT INTO OTHER ACCESS TECHNOLOGIES, SUCH AS INTERNET TELEPHONY AND CABLE? HOW WIDESPREAD DO YOU ENVISION SIP DEPLOYMENT INTO OTHER ACCESS TECHNOLOGIES, SUCH AS INTE

17、RNET TELEPHONY AND CABLE? 3.7 DESCRIBE IMPLEMENTATION BENEFITS OR CHALLENGES FACED WITH H.323S BINARY REPRESENTATION OF MESSAGES, BASED ON ASN.1 AND PACKED ENCODING RULES. INCLUDE CONSIDERATIONS FOR INTEROPERABILITY, REUSE, ETC. DESCRIBE IMPLEMENTATION BENEFITS OR CHALLENGES FACED WITH SIPS TEXT ENC

18、ODING OF MESSAGES, SIMILAR TO HTTP AND RTSP. INCLUDE CONSIDERATIONS FOR INTEROPERABILITY, REUSE, ETC. COMPARE THE BENEFITS AND CHALLENGES OF THE ENCODING OF THE H.323 PROTOCOL AND THE SIP PROTOCOL. 3.8 DESCRIBE AND COMPARE H.323S AND SIPS SUPPORT FOR DISTRIBUTED CALL SIGNALING AND RESOURCE MANAGEMEN

19、T. 47 3.9 DISCUSS AND COMPARE THE INTEROPERABILITY OF AN H.323-BASED UMTS RELEASE 2000 NETWORK AND A SIP-BASED UMTS RELEASE 2000 NETWORK WITH THE EXISTING NETWORKS (WIRELESS AND WIRELINE). IDENTIFY AND COMPARE COMPLEXITIES WITH THE INTERWORKING THAT MIGHT BE PRESENT USING H.323 AND SIP (I.E., GATEWA

20、Y COMPLEXITY). 3.10 DESCRIBE AND COMPARE THE BASIC SET OF SERVICES THAT WOULD BE SUPPLIED IN A UMTS RELEASE 2000 NETWORK WITH H.323 AND SIP IMPLEMENTATION. HOW WOULD ADDITIONAL SERVICES BE ADDED FOR: CARRIER DEFINED, THIRD PARTY DEFINED, AND STANDARDS DEFINED SERVICES? HOW ARE TRIGGER POINTS DEFINED

21、? WHERE ARE THE SERVICES SUPPORTED, VISITED OR HOME NETWORK? 3.11 DESCRIBE AND COMPARE THE OAM&P SERVICES THAT WOULD BE SUPPORTED IN A UMTS RELEASE 2000 WITH H.323 AND SIP IMPLEMENTATION. 3.12 DISCUSS AND COMPARE HOW ACCOUNTING AND BILLING WOULD BE PERFORMED IN THE UMTS RELEASE 2000 NETWORK WITH H.3

22、23 AND SIP. 3.13 ASSUMING FIRM STANDARDS TEXT EXISTS FOR AN H.323 IMPLEMENTATION IN THE UMTS RELEASE 2000 ARCHITECTURE BY 4Q00, IS IT POSSIBLE TO HAVE GENERAL AVAILABILITY OF AN UMTS RELEASE 2000 NETWORK WITH H.323 MULTIMEDIA CALL CONTROL SOLUTION DEPLOYED BY THE END OF 2Q 2001 WITH THIS ARCHITECTUR

23、E? 3.14 ASSUMING FIRM STANDARDS TEXT EXISTS FOR AN SIP IMPLEMENTATION IN THE UMTS RELEASE 2000 ARCHITECTURE BY 4Q00, IS IT POSSIBLE TO HAVE GENERAL AVAILABILITY OF AN UMTS RELEASE 2000 NETWORK WITH SIP MULTIMEDIA CALL CONTROL SOLUTION DEPLOYED BY THE END OF 2Q 2001 WITH THIS ARCHITECTURE? 3.15 PLEAS

24、E IDENTIFY WHICH, IF ANY, OF THE UMTS RELEASE 2000 DEFINED INTERFACES YOU BELIEVE WILL BE PROPRIETARY AVAILABLE IN 2Q2001. 3.16 DESCRIBE ANY ALTERNATE MEANS OF STAGING DEPLOYMENT OF FUNCTION TO FACILITATE THE INTRODUCTION FOR THIS ARCHITECTURE. 3.17 DESCRIBE AND COMPARE HOW A SUBSCRIBER OBTAINS A CO

25、NSISTENT AND FULL SET OF SERVICES, NO MATTER WHAT NETWORK THEY MAY BE LOCATED IN, USING THE UMTS RELEASE 2000 ARCHITECTURE WITH H.323 AND SIP SIGNALING. SPECIFICALLY ADDRESS WHICH NETWORK ELEMENTS IN BOTH THE VISITED AND HOME NETWORKS WOULD BE INVOLVED AND REQUIRE SIGNALING INTERACTION, WHAT ELEMENT

26、 CONTROLS BEARER RESOURCES, ETC. 3.18 FOR THE PURPOSE OF HIGHLIGHTING AND COMPARING THE SIGNALING COMPLEXITIES, PROVIDE EXAMPLE CALL FLOWS USING BOTH H.323 AND SIP SIGNALING AND THE UMTS RELEASE 2000 ARCHITECTURE TO SUPPORT ONE OR MORE OF THE FOLLOWING SERVICES: 51 3.18.1 Mobile originated call to a

27、 landline phone 51 3.18.2 Mobile originated call to a mobile phone 3.18.3 Mobile terminated call from a landline phone 53 3.18.4 Mobile terminated call from a mobile phone 3.18.5 Mobile party adding in a third party (landline) in an existing mobile to landline connected call 3.18.6 Landline party ad

28、ding in a third party (mobile on UMTS Release 2000 network) in an existing landline to landline connected call 3.18.7 Mobile terminated call from a landline phone, mobile busy, forwarded to voice mail 3.18.8 Mobile terminated call from a landline phone, no answer, forwarded to subscriber defined mob

29、ile phone 3.18.9 Mobile originated call while roaming in another UMTS Release 2000 network 3.18.10 Mobile terminated call while roaming in another UMTS Release 2000 network 3.18.11 Mobile originated call while roaming in another 3GPP network 3.18.12 Mobile terminated call while roaming in another 3G

30、PP network 3.18.13 SIM roaming into a UMTS Release 2000 network 3.19 DESCRIBE AND COMPARE THE SECURITY MECHANISMS IN PLACE WITH H.323 AND SIP, AND HOW THESE MECHANISMS MEET OPERATOR REQUIREMENTS FOR FRAUD MITIGATION AND END-USER PRIVACY. 3.20 EXPLAIN HOW THE UMTS RELEASE 2000 ARCHITECTURE WITH THE H

31、.323 AND SIP PROTOCOLS SUPPORT REGULATORY SERVICES, SUCH AS LAWFUL SURVEILLANCE AND EMERGENCY SERVICES (INCLUDING LOCATION). 71 3.21 RECOMMENDATION 3.21.1 CONCLUSION 3.22 REFERENCES 74 1 Background Two standards have emerged for signaling and control of VoIP telephony: ITU-T H.323 and the IETF Sessi

32、on Initiated Protocol (SIP). These protocols, although resulting in the same end-user service (telephony), differ in the approach to providing signaling functions. H.323 is based more on a monolithic bloc derived from H.320 for traditional of the traditional circuit-switched ISDN multimedia, and SIP favors a more lightweight approach based on